Blood Sciences Test


TSH (Thyroid Stimulating Hormone)

Specimen

Serum

Units

miu/L

Reference Range

0.27 – 4.2 miu/L

Test Usage for monitoring patients on replacement Thyroxine

If TSH <0.35, Patient overtreated – reduce dose and retest after 4-6 weeks.   This guidance is not applicable for pregnancy, thyroid cancer, or secondary hypothyroidism due to pituitary or hypothalamic disorders.

 

If TSH within normal range then acceptable if asymptomatic, repeat test annually. Symptomatic patients may benefit from reducing TSH below 1.0mU/L, but avoid suppressing TSH below the reference range.   This guidance is not applicable for pregnancy, thyroid cancer, or secondary hypothyroidism due to pituitary or hypothalamic disorders.

 

If TSH >4.5 Patient Undertreated – if taking medication as prescribed, increase dose and retest in 4-6 weeks. This guidance is not applicable for pregnancy, thyroid cancer, or secondary hypothyroidism due to pituitary or hypothalamic disorders.

Availability

Local test

Turnaround Time

1 day

Can be added on to an existing request up to 4 days following sample receipt

Minimum Repeat Interval

25 days

Specimen Labelling Procedure